Madeleine Simms, who has died aged 81, was one of the architects of the 1967 Abortion Act and a campaigner on a range of social issues. It was a year after the birth of her first child, Nick, in 1959 that Madeleine first became aware that abortion was illegal in Britain. While the social injustice involved in private abortion being available for the rich but not the poor appalled her, her main motivation was the thought of the neglect or abuse of unwanted children. She joined the Abortion Law Reform Association (ALRA), and became active after the role of thalidomide in causing birth defects was realised in 1961.

Madeleine was devoted to her children. She was to say: "Some of our political opponents in the 1960s really did believe that those who were in favour of having children by choice, not chance, disliked children. So they were quite surprised that between us we had so many. I remember being amused by this thought when I was correcting proofs of an article about abortion law reform while sitting in bed at University College hospital awaiting the birth of my second child [Harriet, in 1965]."

Madeleine could seem formidable. Her cool and analytical mind was always in evidence, but on further acquaintance, the warmth and passion she brought to the things she felt were important became apparent. Unlike the original ALRA members, whom she felt were restrained and discreet, Madeleine and her fellows wrote letters to the press and MPs and, supported by parliamentarians such as Douglas Houghton and Roy Jenkins, they pioneered the sort of proactive lobbying that is now common, asking MPs lucky in the annual private members' ballot to sponsor an abortion bill. Eventually they found David Steel (Lord Steel of Aikwood).

Madeleine, now press officer and editor of the ALRA newsletter, was pragmatic. While she always felt the bill was not ideal, it was a start. After it was passed, she and her colleagues – Diane Munday, Alastair Service, Vera Houghton and Dilys Cossey – had to fight many attempts to abolish or water down the 1967 Abortion Act, while she would have preferred it to be more radical.

In 1971 Madeleine went to Bedford College, London (now Royal Holloway, University of London), to do a degree in medical sociology. There she met the social scientist Ann Cartwright, director of the Institute for Social Studies in Medical Care, and became deputy director. She was a trustee of the Birth Control Trust and the Simon Population Trust, and when seconded to the Department of Health research management division, wrote many articles, pamphlets and reports on sexual health and women's rights with fluency and precision.

Her principal work is probably Abortion Law Reformed (1971), with Keith Hindell, but the research reports Non-medical Abortion Counselling (1973) and Teenage Mothers and Their Partners (1991) are as relevant now as they were when written.

She was born Madeleine Zimmerman in Vienna. Her Jewish parents made their home in London when she was a few months old. Her family were, unsurprisingly, always political – she was taken to hear Aneurin Bevan at the age of 15 – and she went from heated discussions at home to debates with fellow pupils such as Shirley Williams at St Paul's girls' school. She went to Aberdeen University in 1948 to read moral philosophy and English literature, but she added political economy and logic and metaphysics as subsidiary subjects, and international relations "just out of interest".

She began the way she would continue, soon running the university's socialist society, the philosophical society and the peace with China movement, joining the committee that tried to have Paul Robeson, the black American singer and activist, elected rector of the university, and the student council. She always said she joined for a social life, finding Aberdeen dour after London, but those who knew her suspected it was just a taste of things to come.

On graduation Madeleine joined the press office of Unilever, but when, according to friends, her mother asked her "to find a nice Jewish boy", she tried the Jewish Graduates' Association, and walked off with the chairman, Dennis Simms, like her an atheist, whom she married in 1956.

When he died, less than a year ago, the traumatic event prompted one of her final campaigns. She wrote, eloquently and personally, to the Commission on Assisted Dying in favour, as always, of choice.

Her influence may have been far more profound than to have given women choice over a pregnancy. It has been said that the Abortion Act was a result of the women's movement, but in fact it was the other way round. The 1960s campaign for abortion law reform was the foundation for the women's movement in the 70s. Without the possibility of planning lives and careers that reproductive choice gave, the movement would have stalled.

Madeleine is survived by Nick, Harriet and two grandchildren.

Julie Bindel writes: The last time I saw Madeleine was at the 60th wedding anniversary of my in-laws, her friends Ernest and Enid Wistrich. Tributes to the couple were invited and many told stories of the happy relationship. Not so Madeleine. She made a political speech about the origins of the campaign to legalise abortion, focusing on how she persuaded Ernest, in 1966, to introduce a private members' bill were he elected to parliament. He was not.

Madeleine was a formidable character, always ready to engage in political discussion and debate. Possessed of a forceful yet warm personality and an excellent sense of humour, she would enthusiastically recount her latest campaigning activities. Seeing her with Dennis was heart-warming, as their relationship was so obviously built on mutual love and respect, with him supporting her all the way in her political efforts.

• Madeleine Simms, rights campaigner, born 6 September 1930; died 3 October 2011